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Nawaz, M. A., Khan, B. U., Mahmood, A., Younas, M., Din, J. U, Sutherland, C. (2021). An empirical demonstration of the effect of study design on density estimations. Nature, 11(13104), 1–9.
Abstract: The simultaneous development of technology (e.g. camera traps) and statistical methods, particularly spatially capture–recapture (SCR), has improved monitoring of large mammals in recent years. SCR estimates are known to be sensitive to sampling design, yet existing recommendations about trap spacing and coverage are often not achieved, particularly for sampling wide-ranging and rare species in landscapes that allow for limited accessibility. Consequently, most camera trap studies on large wide-ranging carnivores relies on convenience or judgmental sampling, and often yields compromised results. This study attempts to highlight the importance of carefully considered sampling design for large carnivores that, because of low densities and elusive behavior, are challenging to monitor. As a motivating example, we use two years of snow leopard camera trapping data from the same areas in the high mountains of Pakistan but with vastly different camera configurations, to demonstrate that estimates of density and space use are indeed sensitive to the trapping array. A compact design, one in which cameras were placed much closer together than generally recommended and therefore have lower spatial coverage, resulted in fewer individuals observed, but more recaptures, and estimates of density and space use were inconsistent with expectations for the region. In contrast, a diffuse design, one with larger spacing and spatial coverage and more consistent with general recommendations, detected more individuals, had fewer recaptures, but generated estimates of density and space use that were in line with expectations. Researchers often opt for compact camera configurations while monitoring wide-ranging and rare species, in an attempt to maximize the encounter probabilities. We empirically demonstrate the potential for biases when sampling a small area approximately the size of a single home range—this arises from exposing fewer individuals than deemed sufficient for estimation. The smaller trapping array may also underestimate density by significantly inflating ?. On the other hand, larger trapping array with fewer detectors and poor design induces uncertainties in the estimates. We conclude that existing design recommendations have limited utility on practical grounds for devising feasible sampling designs for large ranging species, and more research on SCR designs is required that allows for integrating biological and habitat traits of large carnivores in sampling framework. We also suggest that caution should be exercised when there is a reliance on convenience sampling.
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Nawaz, M. A., Khan, B. U., Mahmood, A., Younas, M., Din, J. U, Sutherland, C. (2021). An empirical demonstration of the effect of study design on density estimations. Nature, 11(13104), 1–9.
Abstract: The simultaneous development of technology (e.g. camera traps) and statistical methods, particularly spatially capture–recapture (SCR), has improved monitoring of large mammals in recent years. SCR estimates are known to be sensitive to sampling design, yet existing recommendations about trap spacing and coverage are often not achieved, particularly for sampling wide-ranging and rare species in landscapes that allow for limited accessibility. Consequently, most camera trap studies on large wide-ranging carnivores relies on convenience or judgmental sampling, and often yields compromised results. This study attempts to highlight the importance of carefully considered sampling design for large carnivores that, because of low densities and elusive behavior, are challenging to monitor. As a motivating example, we use two years of snow leopard camera trapping data from the same areas in the high mountains of Pakistan but with vastly different camera configurations, to demonstrate that estimates of density and space use are indeed sensitive to the trapping array. A compact design, one in which cameras were placed much closer together than generally recommended and therefore have lower spatial coverage, resulted in fewer individuals observed, but more recaptures, and estimates of density and space use were inconsistent with expectations for the region. In contrast, a diffuse design, one with larger spacing and spatial coverage and more consistent with general recommendations, detected more individuals, had fewer recaptures, but generated estimates of density and space use that were in line with expectations. Researchers often opt for compact camera configurations while monitoring wide-ranging and rare species, in an attempt to maximize the encounter probabilities. We empirically demonstrate the potential for biases when sampling a small area approximately the size of a single home range—this arises from exposing fewer individuals than deemed sufficient for estimation. The smaller trapping array may also underestimate density by significantly inflating
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Oberosler, V., Tenan, S., Groff, C., Krofel, M., Augugliaro, C., Munkhtsog, B., Rovero, F. (2021). First spatially‐explicit density estimate for a snow leopard population in the Altai Mountains. Biodiversity and Conservation, , 15.
Abstract: The snow leopard Panthera uncia is an elusive and globally-threatened apex predator occurring in the mountain ranges of central Asia. As with other large carnivores, gaps in data on its distribution and abundance still persist. Moreover, available density estimates are often based on inadequate sampling designs or analytical approaches. Here, we used camera trapping across a vast mountainous area (area of the sampling frame 850 km2; analysed habitat extent 2600 km2) and spatially-explicit capture-recapture (SECR) models to provide, to our knowledge, the first robust snow leopard population density estimate for the Altai Mountains. This region is considered one of the most important conservation areas for snow leopards, representing a vast portion of suitable habitat and a key ecological corridor. We also provide estimates of the scale parameter (σ) that reflects ranging behaviour (activity range) and baseline encounter probability, and investigated potential drivers of density and related parameters by assessing their associations with anthropogenic and environmental factors. Sampling yielded 9729 images of snow leopards corresponding to 224 independent detections that belonged to a minimum of 23 identified adult individuals. SECR analysis resulted in an overall density of 1.31 individuals/100 km2 (1.15%–1.50 95% CI), which was positively correlated with terrain slope. This estimate falls within the mid-values of the range of density estimates for the species globally. We estimated significantly different activity range size for females and males (79 and 329 km2, respectively). Base- line encounter probability was negatively associated with anthropogenic activity. Our study contributes to on-going efforts to produce robust global estimates of population abundance for this top carnivore.
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Pahuja, M., Sharma, R. K. (2021). Wild Predators, Livestock, and Free Ranging Dogs: Patterns of Livestock Mortality and Attitudes of People Toward Predators in an Urbanizing Trans-Himalayan Landscape. Frontiers in Conservation Science, 2(109), 1–13.
Abstract: Livestock depredation by large carnivores is a significant source of conflicts over predators and an important conservation and economic concern. Preventing livestock loss to wild predators is a substantial focus of human-carnivore conflict mitigation programs. A key assumption of the preventive strategy is reduction in the livestock losses leading to a positive shift in the attitudes toward predators. Therefore, it is important to quantify the true extent of livestock mortality caused by wild predators and its influence on attitudes of the affected communities. We examined seasonal and spatial patterns of livestock mortality and factors influencing people’s attitudes toward wild predators i.e., snow leopards (Panthera uncia) and wolves (Canis lupus chanco) and free-ranging dogs (Canis lupus familiaris) in a Trans-Himalayan urbanizing landscape in India. We used systematic sampling to select the survey households and implemented a semi- structured questionnaire to respondents. The sampled villages (n = 16) represent a mosaic of urban and agricultural ecosystems within a radius of 40 km of Leh town. In 2016–2017, 93% of the sampled households lost livestock to predators, accounting for 0.93 animals per household per year. However, of the total events of livestock mortality, 33% were because of weather/natural events, 24% by snow leopards, 20% because of disease, 15% because of free-ranging dogs and 9% because of wolves. The annual economic loss per household because of livestock mortality was USD 371, a substantial loss given the average per capita income of USD 270 in the region. Of the total loss, weather/natural events caused highest loss of USD 131 (35%), followed by snow leopards USD 91 (25%), disease USD 87 (24%), free ranging dogs USD 48 (13%), and wolves USD 14 (4%). Despite losing a considerable proportion of livestock (33 %) to wild predators, respondents showed a positive attitude toward them but exhibited neutral attitudes toward free-ranging dogs. Gender emerged as the most important determinant of attitudes toward wild predators, with men showing higher positive attitude score toward wild predators than women. Our findings highlight the context specific variation in human-wildlife interactions and emphasize that generalizations must be avoided in the absence of site specific evidence.
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Pal, R., Sutherland, C., Qureshi, Q., Sathyakumar, S. (2021). Landscape connectivity and population density of snow leopards across a multi-use landscape in Western Himalaya. Animal Conservation, . Retrieved April 28, 2024, from http://dx.doi.org/https://doi.org/10.1111/acv.12754
Abstract: Human modification and habitat fragmentation significantly impact large carnivores requiring large, connected habitats to persist in a landscape. Understanding species responses to such change and the protection of critical areas and connectivity they provide is essential when planning effective conservation strategies. Our study examines the spatial distribution of the snow leopard (Panthera uncia) across a gradient of protection status, anthropogenic pressures and habitat types in the Gangotri landscape (~4600 km2), Western Himalaya. Using spatial capture-recapture modeling, we analyzed a 4-year camera trapping dataset (2015–2019) to assess the relationship between snow leopard movement and topography and identified the conducible areas for facilitating movement across the landscape. Snow leopard density was positively associated with elevation and slope, and was higher in protected areas (summer: 1.42 SE 0.02/100km2; winter 2.15 SE 0.03 vs. summer: 0.4 SE 0.01; winter: 0.6 SE 0.01 for unprotected areas). Precipitous terrain and several prominent mountain peaks were found to be resistant to snow leopard movement. Even with a range of human activities inside protected areas, the higher density suggests a positive impact of protection. Density-weighted connectivity showed that conducible areas are available between the Gangotri landscape and the adjacent protected areas. However, compared to protected area, these areas are relatively less used and require attention for management. We recommend regulating human activities and co-managing pastures with local communities to revive prey base outside protected areas, especially in corridors, to ensure such areas are functionally conducive. Our study provides a framework to collectively quantitate the spatial pattern of abundance, distribution and connectivity. Our approach has broad applicability for policymakers to develop strategic plans for balancing the conservation of species, and other land uses in a multi-use landscape.
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Pandey, B. P., Thami, S., Shrestha, R., Subedi, N., Chalise, M. K., Ale, S. B. (2021). Snow leopards and prey in Rolwaling Valley, Gaurishankar Conservation Area, Nepal. CATnews, 74(Windter 2021), 14–19.
Abstract: The snow leopard Panthera uncia, an apex predator of the Himalayan ecosystem, often shares habitat with the wolf, Canis lupus, red fox Vulpes vulpes, and other carnivores. A biodiversity monitoring programme primarily focused on the assessment of the status of snow leopard and its prey in Rolwaling valley of Gaurishankar Conservation Area, Nepal, was carried out during June–November 2019. We deployed single camera traps in each of twelve grids sized 16 km2 each, operated 24 hours, and left alone for the whole study period. A single snow leopard was captured thrice on same camera in Rhododendron anthopogon-Hippophae thibetana scrubland, near Tsho Rolpa glacial lake (4,536 m). Alongwith snow leopard, wolves were also photographed at three sites namely Yelung pass (4,956 m), Tsho Rolpa (4,536 m) and Dudhkunda ridgeline (5,091 m). The red fox was the most frequent predator in Rolwaling while stone marten Martes foina, yellow-throated marten Martes flabigula, and yellow-belied weasel Mustella katiyah were captured occasionally. Photo capture rate index PCRI per 100 trap nights was calculated for all identifiable species where snow leopard and wolf had PCRI values of 0.35 and 0.71, respectively. The Cumulative PCRI values suggest a pyramid shaped community structure in Rolwaling with small herbivores (including game birds) with broad base (PCRI 22.29) followed by large herbivores (10.38) and small-medium sized carnivores (6.96). The top predators (snow leopard and wolf) produces 1.06 photographic rate index. The declaration of Gaurishankar conservation area and continuous efforts from conservation area management committees, strict cultural rules from local Buddhist community in the valley are found possibly favoured the recolonization of the wolf and frequent visits by snow leopard.
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Rashid, W., Shi, J., Rahim, I. U., Qasim, M., Baloch, M. N., Bohnett, E., Yang, F., Khan, I., Ahmad, B. (2021). Modelling Potential Distribution of Snow Leopards in Pamir, Northern Pakistan: Implications for Human–Snow Leopard Conflicts. Sustainability, 13(13229), 1–15.
Abstract: The snow leopard (Panthera uncia) is a cryptic and rare big cat inhabiting Asia’s remote and harsh elevated areas. Its population has decreased across the globe for various reasons, includ
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Rode, J., Lambert, C., Marescot, L., Chaix, B., Beesau, J., Bastian, S., Kyrbashev, J., Cabanat, A.L. (2021). Population monitoring of snow leopards using camera trapping in Naryn State Nature Reserve, Kyrgyzstan, between 2016 and 2019. Global Ecology and Conservation, 31(e01850), 1–6.
Abstract: Four field seasons of snow leopard (Panthera uncia) camera trapping inside Naryn State Nature Reserve, Kyrgyzstan, performed thanks to citizen science expeditions, allowed detecting a minimal population of five adults, caught every year with an equilibrated sex ratio (1.5:1) and reproduction: five cubs or subadults have been identified from three litters of two different females. Crossings were observed one to three times a year, in front of most camera traps, and several times a month in front of one of them. Overlap of adults’ minimal territories was observed in front of several camera traps, regardless of their sex. Significant snow leopard presence was detected in the buffer area and at Ulan area which is situated at the reserve border. To avoid poaching on this apex predator and its preys, extending the more stringent protection measures of the core zone to both the Southern buffer area and land adjacent to Ulan is recommended.
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Salvatori, M., Tenan, S., Oberosler, V., Augugliaro, C., Christe, P., Groff, C., Krofel, M., Zimmermann, F., Rovero, F. (2021). Co-occurrence of snow leopard, wolf and Siberian ibex under livestock encroachment into protected areas across the Mongolian Altai. Biological Conservatio, 261(109294), 1–14.
Abstract: In countries such as Mongolia, where globalization of the cashmere market has spurred herders to massively increase their livestock numbers, an important conservation concern is the effect of livestock encroachment on wildlife. This is especially important inside protected areas (PAs), which often represent the last refugia for threatened large mammals. We used camera-traps to sample four areas with different protection status across the Mongolian Altai Mountains, and targeted a predator-prey system composed of livestock, one large herbivore, the Siberian ibex, and two large carnivores, the snow leopard and the wolf. To determine the effect of livestock on habitat use by the wild species and their spatio-temporal co-occurrence we applied an occupancy framework explicitly developed for modelling interacting species. We recorded a widespread presence of domestic animals in the PAs, and observed avoidance of sites used by livestock by snow leopard and ibex, while wolves tended to co-occur with it. Snow leopard and ibex showed clear mutual co-occurrence, indicating a tight predator-prey relationship. Results provide evidence that, at the scale of sites sampled primarily to maximise snow leopard detections, grazing livestock interferes with wild species by inducing avoidance in snow leopards, and attraction in wolves. We suggest that (1) PAs management should enforce real grazing limitations on the ground, especially in the core areas of the parks; (2) new policies incorporating wildlife conservation into government subsidies to pastoralists should be envisaged, to prevent increasing displacement of snow leopards and ibex; (3) as wolves co- occurred with livestock, with the potential for human-wildlife conflicts, we encourage the use of a set of prevention techniques to mitigate livestock depredation.
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Shao, X., Lu, Q., Xiong, M., Bu, H., Shi, X., Wang, D., Zhao, J., Li, S., Yao, M. (2021). Prey partitioning and livestock consumption in the world’s richest large carnivore assemblage. Current Biology, 31, 4887–4897.
Abstract: Large mammalian carnivores have undergone catastrophic declines during the Anthropocene across the world. Despite their pivotal roles as apex predators in food webs and ecosystem dynamics, few detailed di- etary datasets of large carnivores exist, prohibiting deep understanding of their coexistence and persistence in human-dominated landscapes. Here, we present fine-scaled, quantitative trophic interactions among sym- patric carnivores from three assemblages in the Mountains of Southwest China, a global biodiversity hotspot harboring the world’s richest large-carnivore diversity, derived from DNA metabarcoding of 1,097 fecal sam- ples. These assemblages comprise a large-carnivore guild ranging from zero to five species along with two mesocarnivore species. We constructed predator-prey food webs for each assemblage and identified 95 vertebrate prey taxa and 260 feeding interactions in sum. Each carnivore species consumed 6–39 prey taxa, and dietary diversity decreased with increased carnivore body mass across guilds. Dietary partitioning was more evident between large-carnivore and mesocarnivore guilds, yet different large carnivores showed divergent proportional utilization of different-sized prey correlating with their own body masses. Large car- nivores particularly selected livestock in Tibetan-dominated regions, where the indigenous people show high tolerance toward wild predators. Our results suggest that dietary niche partitioning and livestock subsidies facilitate large-carnivore sympatry and persistence and have key implications for sustainable conservation promoting human-carnivore coexistence.
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